Nitroxides. IX. Synthesis of nitroxide free radical α-amino acids

1982 ◽  
Vol 60 (12) ◽  
pp. 1448-1451 ◽  
Author(s):  
László Lex ◽  
Kálmán Hideg ◽  
H. Olga Hankovszky
Keyword(s):  
Amino Acids ◽  
Free Radical ◽  
Amino Acid ◽  
Propionic Acid ◽  
Nitroxide Free Radical ◽  
Stable Nitroxide

Three methods are described for preparation of a new stable nitroxide free radical amino acid, 2-amino-3-(1-oxyl-2,2,5,5-tetramethyl-3-pyrrolin-3-yl) propionic acid and its derivates. This amino acid may be used as a paramagnetic amino acid synthon in studies of peptides.

Changes in amino acid compounds of wheat plants during ensiling and aerobic exposure: the influence of propionic acid and urea phosphate-calcium propionate

1984 ◽  
Vol 102 (3) ◽  
pp. 667-672 ◽  
Author(s):  
G. Ashbell ◽  
H. H. Theune ◽  
D. Sklan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Propionic Acid ◽  
Butyric Acid ◽  
Total Amino Acid ◽  
Amino Butyric Acid ◽  
Urea Phosphate ◽  
Fresh Material ◽  
Calcium Propionate

SummaryChanges in distribution of amino acid nitrogen of chopped wheat plants ensiled at shooting and flowering when wilted, and at the milk and dough stages as fresh material, were determined as affected by addition of 0·8% propionic acid (PrA) or 2·2% urea phosphate-calcium propionate (UP-CaPr). Analyses were carried out after an ensiling period of 90 days and after a further aerobic exposure period (AE) of 7 days.Total amino acid (TAA) contents in the dry matter (D.M.) during the fermentation period and in the AE were stable in untreated material (UM) and treated material. Concentration of essential amino acids decreased during fermentation, this decrease being higher in the UM. The free amino acids were low in the fresh material (18·6% of TAA) but increased in the ensiled material to ca. 71 % of the TAA in the silage. In the AE this level was 63% in UM and 69% in treated material. The ammonia-N contents increased during fermentation in UM and especially in the UP-CaPr treatments, while the opposite occurred in the PrA treatments.The concentrations of and changes in 21 amino acids (AAs) are given. The highest AA concentrations recorded in the fresh material were those of arginine, lysine, glutamic acid, alanine, leucine, proline and glycine. The most marked increments in AAs as a result of fermentation were those of ornithine, γ-amino butyric acid, threonine and methionine. Marked decreases were observed in glutamine, arginine and glutamic acid. PrA increased mainly arginine, asparagine and glutamine, whereas γ-amino butyric acid decreased; UP-CaPr increased arginine, asparagine, lysine and glutamic acid (in silage only) and reduced γ-amino butyric acid and glutamine (in AE only).

An experimental NEXAFS and computational TDDFT and ΔDFT study of the gas-phase core excitation spectra of nitroxide free radical TEMPO and its analogues

2016 ◽  
Vol 18 (15) ◽  
pp. 10207-10217 ◽  
Author(s):  
Ivan Ljubić ◽  
Antti Kivimäki ◽  
Marcello Coreno
Keyword(s):  
Free Radical ◽  
Gas Phase ◽  
Excitation Spectra ◽  
Core Excitation ◽  
The Core ◽  
Nitroxide Free Radical ◽  
Phase Spectra ◽  
Stable Nitroxide

Core excitation (NEXAFS) C 1s, N 1s, and O 1s gas-phase spectra of stable nitroxide free radical TEMPO and two of its amide-substituted analogues are assigned from the onset of the absorptions to the vicinity of the core-ionization thresholds using the theoretical TDDFT and ΔDFT methods.

scholarly journals Dietary supplementation of propionylated starch to domestic cats provides propionic acid as gluconeogenic substrate potentially sparing the amino acid valine

2014 ◽  
Vol 3 ◽  
Author(s):  
Kristel Rochus ◽  
An Cools ◽  
Geert P. J. Janssens ◽  
Lynn Vanhaecke ◽  
Birgitte Wuyts ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Propionic Acid ◽  
Protein Intake ◽  
Protein Digestibility ◽  
Domestic Cats ◽  
Intake Level ◽  
Health And Disease ◽  
And Control ◽  
Gluconeogenic Substrate

AbstractIn strict carnivorous domestic cats, a metabolic competition arises between the need to use amino acids for gluconeogenesis and for protein synthesis both in health and disease. The present study investigated the amino acid-sparing potential of propionic acid in cats using dietary propionylated starch (HAMSP) supplementation. A total of thirty cats were fed a homemade diet, supplemented with either HAMSP, acetylated starch (HAMSA) or celite (Control) for three adaptation weeks. Propionylated starch was hypothesised to provide propionic acid as an alternative gluconeogenic substrate to amino acids, whereas acetic acid from HAMSA would not provide any gluconeogenic benefit. Post-adaptation, a 5-d total faecal collection was carried out to calculate apparent protein digestibility coefficients. Fresh faecal and blood samples were collected to analyse fermentation endproducts and metabolites. The apparent protein digestibility coefficients did not differ between supplements (P = 0·372) and were not affected by the protein intake level (P = 0·808). Faecal propionic acid concentrations were higher in HAMSP than in HAMSA (P = 0·018) and Control (P = 0·003) groups, whereas concentrations of ammonia (P = 0·007) were higher in HAMSA than in HAMSP cats. Tendencies for or higher propionylcarnitine concentrations were observed in HAMSP compared with HAMSA (P = 0·090) and Control (P = 0·037) groups, and for tiglyl- + 3-methylcrotonylcarnitine concentrations in HAMSP as compared with Control (P = 0·028) cats. Methylmalonylcarnitine concentrations did not differ between groups (P = 0·740), but were negatively correlated with the protein intake level (r –0·459, P = 0·016). These results suggest that HAMSP cats showed more saccharolytic fermentation patterns than those supplemented with HAMSA, as well as signs of sparing of valine in cats with a sufficient protein intake.

scholarly journals Nutritional, phytoconstituents, and free radical scavenging potentials of Cola lepidota K. Schum. and Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill. leaves

2020 ◽  
Vol 7 (15) ◽  
pp. 43-57
Author(s):  
Agada Adaeze Bob-Chile ◽  
Peter Uchenna Amadi
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Free Radical ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Radical Scavenging ◽  
Essential Amino Acids ◽  
Free Radical Scavenging ◽  
Total Amino Acid ◽  
Irvingia Gabonensis

This study was carried out to determine the essential oil components, protein qualities, fatty acid composition, and free radical scavenging potentials of leaves of Cola lepidota K. Schum. (Malvaceae) and Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill. (Irvingiaceae) using chromatographic and spectrophotometric methods. Thirty five bioactive components were isolated from C. lepidota leaves with myrcene, phytol, ephedrine, hexadecanoic acid, and 1,14-tetradecanediol as the main compounds while phytol, 2-furancarboxaldehyde, 5-(hydroxymethyl)-, 1-hexadecyne, carotene, and humulene were the predominant components of the I. gabonensis leaves. Leucine and arginine were the predominant essential amino acids, whereas glutamic acid and serine were the main non-essential amino acids in both leaves. The total amino acid (TAA) (70.92 g/100g), total non-essential amino acid (TNEAA) (45.87 g/100 g), and total acidic amino acid (TAAA) (23.01 g/100 g) of C. lepidota were high whereas I. gabonensis recorded higher Total essential amino acid (TEAA) (28.98 g/100 g), total aromatic amino acid (TArAA) (7.21 g/100 g), total branched chain amino acid (TBCAA) (14.28 g/100g), predicted protein efficiency ratios (P-PERs), and essential amino acid index (EAAI). C. lepidota contained 55.72% of unsaturated fatty acids, with predominance of linolenic and linoleic acids, while I. gabonensis produced 74.46% of saturated fatty acids, having myristic, lauric, and palmitic acid as the main compounds. All the radical scavenging potentials of both leaves were concentration dependent and produced higher DPPH, hydrogen peroxide, and ABTS radical scavenging potentials than the standards. This study has thus provided the scientific backing for the inclusion of both leaves for dietary and therapeutic purposes.

Evaluation of Bioactive Component, Free Radical Scavenging Potentials and Protein Qualities of Gomphrena celosoides and Zea mays Leaves

2020 ◽  
Vol 16 (7) ◽  
pp. 1108-1115
Author(s):  
Bob-Chile A. Adaeze ◽  
Peter U. Amadi
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Amino Acid ◽  
Unsaturated Fatty Acids ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Bioactive Components

Background: The assessment of underexploited leaves has become crucial to supplement the rapidly depleting sources of bioactive components as well as provide available nutrient sources for local inhabitants. Methods: This study thus investigated the bioactive components of the oil, and fatty acid composition, free radical scavenging potentials, and protein qualities of leaves of Z. mays and G. celosioides using standard methods. The bioactive components of the oils and fatty acids were determined by Gas Chromatograpy, while the amino acid and in-vitro antioxidant potentials were determined using a Technicon Sequential Multi-Sample (TSM) Amino Acid Analyzer, and spectrophotometer, respectively. Results: The Z. Mays leaves showed the abundance of farnesene, hexadecanoic acids, and caryophellene while G. celosioides produced high level of octadecadienoic acid, hexadecanoic acid, and phytol. Z. mays and G. celosioides contained 72.48% and 60.55% unsaturated fatty acids respectively, with the abundance of linolenic acid for Z. mays and oleic acid for G. celosioides. The result for the in vitro antioxidant % inhibition showed a concentration dependent free radical scavenging potentials of the leaves. Both G. celosioides and Z. mays produced greater 1,1-diphenyl-2- picrylhydrazyl (DPPH), and hydrogen peroxide radical scavenging potentials than ascorbic acid, while at 40ppm the nitric oxide and 2,2- azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical % inhibition of Z. mays leaves were lower than those for ascorbic acid. Discussion: The number of essential amino acids in both plants were 48.20 and 39.25 g/100g, total branched chain amino acids (TBCAA) were 21.15 and 16.92 g/100g, predicted protein efficiency ratios (P-PERs) were in the range of 3.02-3.23 and 2.68-2.77, and the essential amino acid index (EAAI) were 1.52 and 1.48, for Z. mays and G. celosioides leaves respectively. Conclusion: From these results, the utilization of Z. mays and G. celosioides for high quality protein, unsaturated fatty acids and potent antioxidant sources, should be massively encouraged.

Photolytic studies on 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, a stable nitroxide free radical

1971 ◽  
Vol 36 (1) ◽  
pp. 209-211 ◽  
Author(s):  
John F. W. Keana ◽  
Robert J. Dinerstein ◽  
Friedhelm Baitis
Keyword(s):  
Free Radical ◽  
Nitroxide Free Radical ◽  
Stable Nitroxide

scholarly journals Desferrioxamine (Desferal) and superoxide free radicals. Formation of an enzyme-damaging nitroxide

1987 ◽  
Vol 246 (3) ◽  
pp. 725-729 ◽  
Author(s):  
M J Davies ◽  
R Donkor ◽  
C A Dunster ◽  
C A Gee ◽  
S Jonas ◽  
...  
Keyword(s):  
Free Radical ◽  
Room Temperature ◽  
Chelation Therapy ◽  
Iron Chelation ◽  
Protonated Form ◽  
Water Soluble ◽  
Iron Chelation Therapy ◽  
Superoxide Free Radical ◽  
Nitroxide Free Radical ◽  
Stable Nitroxide

In neutral solutions, desferrioxamine (Desferal) can react with the superoxide free radical, O2.- (possibly through its protonated form HO2.), to form a relatively stable nitroxide free radical, which can have a half-life of approx. 10 min at room temperature. The formation of the radical can be largely prevented by the presence of superoxide dismutase. The radical reacts rapidly with cysteine, methionine, glutathione, vitamin C and a water-soluble derivative of vitamin E. It also reacts rapidly with alcohol dehydrogenase, causing a loss of enzyme activity. The implications of these findings for mechanistic free-radical biochemistry and iron-chelation therapy could be considerable.

Nitrogen digestion in forage-fed sheep with and without intraruminal propionate infusion

1993 ◽  
Vol 120 (1) ◽  
pp. 107-114 ◽  
Author(s):  
C. J. Seal ◽  
D. S. Parker ◽  
J. Balcells ◽  
J. L. Mole
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gastrointestinal Tract ◽  
Propionic Acid ◽  
Nitrogen Balance ◽  
Free Amino ◽  
Alternative Energy ◽  
Total Amino Acid ◽  
Acid Infusion ◽  
Amino Acid Levels

SUMMARYNitrogen balance and flow of nitrogen along the gastrointestinal tract were determined in growing wether sheep fed a dried grass pellet diet with or without intraruminal propionic acid infusion. Plasma free amino acid and glucose concentrations tended to be higher in peripheral blood of animals receiving propionate (P < 0·10). Overall total nitrogen and amino acid digestibilities and apparent digestibilities of each fraction along the digestive tract were not affected by infusion of propionic acid. The contribution of microbial amino acids to total amino acid flow in the duodenum measured using purine bases as the microbial marker averaged 0·49 and was not affected by propionic acid infusion. It is suggested that changes in circulating amino acid levels arise from reduced utilization of luminal amino acids by gastrointestinal tissues due to the increased availability of alternative energy-yielding substrates.

Synthesis, Equilibrium and Kinetic Properties of Gd3+ Complexes of Three DTPA-Bis(Amide) Derivatives Containing Stable Nitroxide Free Radical Substituents

2003 ◽  
Vol 2003 (19) ◽  
pp. 3601-3608 ◽  
Author(s):  
Zoltán Jászberényi ◽  
Ernő Brücher ◽  
József Jekő ◽  
Kálmán Hideg ◽  
Tamás Kálai ◽  
...  
Keyword(s):  
Free Radical ◽  
Kinetic Properties ◽  
Amide Derivatives ◽  
Nitroxide Free Radical ◽  
Stable Nitroxide
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